Prevalence of tuberculous disease and infection in an urban slum area

Tuberculin test can be read after 24 hours in adolescent children

OBJECTIVE

To assess readability of 24-h tuberculin response in adolescent school children.

DESIGN

Prospective observational study in school.

SUBJECTS

601 healthy adolescent children.

INTERVENTIONS

Tuberculin (1TU PPD RT23 Tween80) was administered and indurations at 24 and 72 h were compared.

MAIN OUTCOME MEASURE

Tuberculin reaction at 24 h.

RESULTS

One hundred twelve children (18.6%) had a positive tuberculin reaction. Prevalence of tuberculin positivity was least (14.2%) in the 10-year age-group and maximum in the 13-year age-group (21.2%). When individual values of tuberculin reaction at 24 and 72 h were compared, a significant difference was noted irrespective of the tuberculin status (t = 8.46, p = 0.001). However, when tuberculin reaction was considered as positive or negative, this difference was not significant (t = 1.89, p > 0.05).

CONCLUSIONS

Tuberculin status in adolescents can be read as positive or negative at 24 h, irrespective of their bacillus Calmette-Guérin scar status.

Tuberculin reactivity in healthy school children in Pondicherry

Five hundred healthy school children in the age group 5-9 years underwent tuberculin testing. Seventy nine per cent of the study population had a BCG scar. 9.2% children were found to be suffering from malnutrition, using the Quetlet's Index and 7.8% were found to be malnourished by weight for age method. 18.6% of the children were tuberculin positive (induration > or = 10 mm) and the prevalence of tuberculin positivity increased with age. The numbers of tuberculin reactors or the mean tuberculin reaction were not affected by malnutrition. BCG scar status neither affected the mean tuberculin size nor the number of tuberculin reactors.